2/3-(5/6-3/4)÷3/8 =2/3-1/12×8/3=2/3-2/9=4/95/14÷{6/7×(4/9+1/6)} =5/14÷(6/7×7/18)=5/14÷1/3=15/14
2/3-(5/6-3/4)÷3/8=2/3-1/12×8/3=2/3-2/9=4/9 5/14÷{6/7×(4/9+1/6)} =5/14÷{6/7×11/18}=5/14÷11/21=15/22